1. Field of the Invention
The present invention relates to a shifter gear.
2. Description of Background Art
A shifter gear is known that meshes with a gear (G6) and is disposed between gears (G2) and (G4) on a gear shift shaft. See, for example, JP-A No. 2011-208766. The shifter gear slides on the shaft by an operation of shift forks (not shown) to selectively mesh with the gear (G2) or the gear (G4). This shifter gear includes a base part, a gear part (a gear part that meshes with the gear (G6)), engaging parts (ring-shaped recessed grooves) with the shift forks, and splines. The gear part is disposed at the outer periphery of this base part. The engaging parts are disposed at the outer periphery of the base part. The splines are disposed at the inner periphery of the base part. The shifter gear is mounted relatively slidable to the gear shift shaft in an axis direction via the splines. The shifter gear is mounted so as to be incapable of relative rotation around the axis. The shift forks engaging the engaging parts perform the slide operation on the shifter gear.
The above-described conventional shifter gear has a large amount of offset between the center of the gear part as a power transmission unit and the center of the spline as the power transmission unit in the axis direction. Thus, due to a load balance of the input and the output of the power, a load in a thrust direction is likely to occur in the shifter gear. Such thrust load causes friction at the engaging part between the shift fork and the shifter gear. Furthermore, the thrust load also acts as a force attempting to bring the shifter gear down in the axial direction, further facilitating the friction.